NO. 1 205. S TN-QPSIS OF THE NA I A DES— SIMPSON. 811 



their sculpture irregularly radial; disks finely concentrically striate, 

 not otherwise sculptured; epidermis yellowish olive, cloth-like; pseudo- 

 cardinals greatly elongated, compressed, sometimes dentellate under the 

 beaks; laterals long, compressed. Animal unknown. 



tNODULARIA SAGITTARIA Lea. 



* Unio Sagittarius Lea, Pr. Ac. N. Sci. Phila., VIII, 1856, p. 93 ; * Jl. Ac. N. Sci. Phila., 



Ill, 1857, p. 298, pi. XXVI, fig. 12; ^ Obs., VI, 1857, p. 18, pi. xxvi, fig. 12. 



* Margaroti ( Unio) Sagittarius Lea, Syn., 1870, p. 58. 



*\Unio dugasti Moklet, Jl. de Conch., XL, 1892, p. 86; 'XLI, 1893, p. 156, pi. m, 

 fig. 4.1 



Siam; Cambodia. 



(Group of Nodular ia ccerulea.) 



Shell elliptical, inflated, pointed about midway up behind, the post- 

 basal region produced, with a well developed posterior ridge; beaks 

 sculjjtured with numerous fine, radiating riblets, the central ones of 

 which join below, the whole often more or less zigzagged and extend- 

 ing well over the disk; epidermis generally bluish green. Animal 

 unknown. 



t NODULARIA C^RULEA Lea. 



""Unio cceruleus Lea, Tr. Am. Phil. Soc, IV, 1831, p. 95, pi. xui, fig. 25; "Obs , I, 

 1834, p. 105, pi. xiii, fig. 25.— ^Hanley, Test. Moll., 1842, p. 194; *Biv. 

 Shells, 1843, p. 194, pi. xx, fig. 49. — *CATLOWaud Reeve, Conch. Nom., 1845, 

 p. 56.— *H. and A. Adams, Gen. Eec. Moll., II. 1857, p. 493.— ^Ciienu, 111. 

 Conch., 1858, pi. xvi, figs. 3, 3a, 36. — *Kuster, Conch. Cab. Unio, 1861, p. 228, 

 pi. Lxxvii, fig. 4.— *SowERBY, Conch. Icon., XVI, 1866, pi. xlii, fig. 230.— 

 *Hanley and Theobald, Conch. Ind., 1876, p. 6, pi. xii, figs. 3, 3a. — "P^etel, 

 Conch. Sam., Ill, 1890, p. 148. 



* Margarita ( Unio) cwrideus Lea, Syn., 1836, p. 26; 1838, p. 20. 

 *Jfa?'(7aron ( C77a'o) cftTM^eifs Lea, Syn., 1852, p. 30; 1870, p. 47. 



* Unio gerUdoni E ydoux, Guer. Mag., 1838, p. 9, pi. cxviii, figs. 2, 2a, 2&.— *Hanley 



and Theobald, Conch. Ind., 1876, p. 6, pi. xii, fig. 2. — *Pjetel, Conch. Sam., 



Ill, 1890, p. 153. 

 *t?7ru'o suhstriatm l^^iA, Pr. Ac. N. Sci. Phila., VIII, 1856, p. 93; ^ Obs., VI, 1857, 



p. 20, pi. XXVI, fig. 14 ; *J1. Ac. N. Sci. Phila., Ill, 1858, pi. xxvi, fig. 14. 

 * Margaron ( Unio) suhsiriatus Lea, Syn., 1870, p. 47. 

 ""iUnio Jmmilis Lea, Pr. Ac. N. Sci. Phila., VIII, 1856, p. 93; *Obs., VI, 1857, p. 16, 



pi. XXVI, fig. 10; *J1. Ac. N. Sci. Phila., Ill, 1858, p. 296, pi. xxvi, fig. 10.— 



"P^TEL, Conch. Sam., Ill, 1890, p. 155. 

 *Margaron ( Unio) humilis Lea, Syn., 1870, p. 32. 

 ^Unio corrianus KusTER, Conch. Cab. Unio, 1861, p. 229, pi. lxvii, fig. 5. 



* t Unio leioma Benson, Ann. and Mag., 1862, p. 192. — * Hanley and Theobald, 



Conch. Ind , 1876, p. 6, pi. xii, fig. 6.—* P.etel, Conch. Sam., Ill, 1890, p. 157. 

 ** t Unio]}ilatti8 Lea, Pr. Ac. N. Sci. Phila., X, 1866, p. 133 ; *J1. Ac. N. Sci. Phila., VI, 

 1868, p. 281, pi. xxxviii, fig. 95 ; * Obs., XII, 1869, p. 41, pi. xxxviii, fig. 95. 



* \ Margaron ( Unio) ijilatus Lea, Syn., 1870, p. 47. 



* t Unio evitatus Lea, Pr. Ac. N. Sci. Phila., X, 1868, p. 133 ; *J1. Ac. N. Sci. Phila., VI, 



1868, p. 279, pi. XXXVIII, fig. 92 ; * Obs., XII, 1869, p. 39, pi. xxxviii, fig. 92. 



'This group seems to stand in part between section Lanceolaria and Nodularia. 



